RESUMO
Eu and Tb doped 17MO-7.88Y2O3-75B2O3 samples were prepared by the solid state reaction. VUV excitation properties and luminescence properties under VUV excitation were studied. Excitation spectra exhibited high absorption in VUV region (120-220 nm). There existed strong emission peaking at 591 and 613 nm corresponding to the 5D0 --> 7F(J) (J = 1, 2, 3, 4) emission transition of Eu3+ when MgO-Y2O3-BO3 : Eu was energized by the VUV radiation (147 nm). By the introduction of Sr into MgO-Y2O3-BO2O3: Eu absorption peaking at 147 nm and red emission peaking at 613 nm are enhanced strongly. Besides the host absorption band of MgO-Y2O3-B2O3 : Tb, there existed strong absorption band peaking at 170, 178, 195, 204, 225 nm corresponding to the 4f(8)-4f(7) 5d transition of Tb3+; emission spectra showed strong emission peaks at 491, 547, 590, 621 nm corresponding to the 5D4 --> 7F(J) (J = 6, 5, 4 and 3) emission transition of Tb3+.
RESUMO
In the present paper, alkaline earth silicates Ba2MgSi2O7 : RE were prepared under a reducing atmosphere by solid-state reaction. Under UV light excitation, Ce3+ doped pyrosilicates phosphors emit efficient bluish violet light. The emission spectra of Eu2+ doped pyrosilicates phosphors showed that Eu2+ ions could occupy two types of sites in Ba2MgSi2O7 host. The energy transfer from Ce2+ to Eu2+ in Ba2MgSi2O7 is efficient, as there is a large overlap between Ce3+ emission bands and Eu2+ excitation bands. Analysis of the spectra of Ce3+ and Tb3+ co-doped phosphor indicated the existence of energy transfer from Ce3+ to Tb3+ in Ba2MgSi2O7 under UV excitation.
